1. Field of the Invention
This invention relates to a color filter which can be used for various apparatuses such as an image input unit of a camera and an image output unit of a display. This invention also relates to a color display apparatus.
2. Description of the Prior Art
A known color filter includes a hologram and a plate having an array of primary color pixels. The hologram and the color pixel array plate are spaced from and parallel to each other. In the known color filter, a light source applies a white light beam to the hologram. The white light beam is diffracted and is separated into a red light beam, a green light beam, and a blue light beam when passing through the hologram. The red light beam, the green light beam, and the blue light beam are focused on a red pixel, a green pixel, and a blue pixel in the color pixel array plate respectively, undergoing modulation and passing through the color pixel array plate. The red light beam, the green light beam, and the blue light beam which have passed through the color pixel array plate form an indicated color image.
In the known color filter, the red light beam, the green light beam, and the blue light beam are incident to the red pixel, the green pixel, and the blue pixel in the color pixel array plate at different angles respectively. These angles of incidence do not correspond to a right angle. Specifically, the paths of the red light beam, the green light beam, and the blue light beam tend to be considerably slant with respect to the color pixel array plate. Accordingly, the known color filter tends to be low in efficiency of use of light.